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<tt>Hi Pierre and Celati,</tt><br>
<tt>First, I should explain that the GDAL driver may have a reported
bug when trying to read overviews. You may experience performance
issues on GDAL 1.9.</tt><br>
<tt>I've reported the bug and it should be fixed on GDAL 1.9.1</tt><br>
<tt><a class="moz-txt-link-freetext" href="http://trac.osgeo.org/gdal/ticket/4649">http://trac.osgeo.org/gdal/ticket/4649</a></tt><br>
<br>
<br>
<tt><big><small>1/What do you think about overviews values ?<br>
Usually, overviews are assigned dividing the image size by 2.
I really don't know what to expect with custom overviews. GDAL
cannot read it at the moment.<br>
<br>
2/According to you, the plugin is abble to display a sql file
with a size of 679 MO ?<br>
It may display with a huge delay. When GDAL's bug is fixed it
should be no problem at all.<br>
<br>
3/In native, these data have 5 bands but we need display only
3 bands. According to you, is it better before importing these
data in database to remove 2 useless bands in order to speed
up the display ?
<br>
That's probably helpfull. I don't really know about how much
it's going to improve, but if you can avoid 66% table size
increase, why not?<br>
<br>
4/Is there update regarding the speed problem ( Gdal driver
issue).<br>
From the link above I assume that it's under development.<br>
<br>
5/Is there another way faster (Gvsig for instance) in
displaying postgis raster data?<br>
I'm not really following GvSIG's development. If they use the
same driver it's most likely that they are running into the
same bug.</small><br>
</big></tt><br>
<br>
<tt>All the Best,</tt><br>
<tt>Mauricio de Paulo</tt><br>
<br>
On 07/10/2012 12:24 PM, Pierre Racine wrote:
<blockquote
cite="mid:87A96661E65C5541AB4D20721C2DD7F8CFBC917A6A@EXCH-MBX-A.ulaval.ca"
type="cite">
<pre wrap="">Mauricio,
We receive many questions regarding the QGIS plugin in the PostGIS user list. Would you prefer us to tell them to ask their question in the QGIS list (now GIS Stack Exchange) or would you we willing to follow postgis-users and answer them when appropriate?
I never use the plugin myself so I am of no help.
Pierre
-----Original Message-----
From: <a class="moz-txt-link-abbreviated" href="mailto:postgis-users-bounces@postgis.refractions.net">postgis-users-bounces@postgis.refractions.net</a> [<a class="moz-txt-link-freetext" href="mailto:postgis-users-bounces@postgis.refractions.net">mailto:postgis-users-bounces@postgis.refractions.net</a>] On Behalf Of celati laurent
Sent: Tuesday, July 10, 2012 7:03 AM
To: <a class="moz-txt-link-abbreviated" href="mailto:postgis-users@postgis.refractions.net">postgis-users@postgis.refractions.net</a>
Subject: [postgis-users] Postgis raster data display
Hello,
I'm trying to display "Raster postgis data" via Qgis ("Load Postgis
Raster Layer"). It works but it's a bit slow!
These raster are 11 Rapideye satellite images with 5 bands in native. I
defined following overviews for each data : 3,9,27,81,243
Size of smallest SQL file : 270 MO
Size of biggest SQL file : 679 MO
1/What do you think about overviews values ?
2/According to you, the plugin is abble to display a sql file with a
size of 679 MO ?
3/In native, these data have 5 bands but we need display only 3 bands.
According to you, is it better before importing these data in database
to remove 2 useless bands in order to speed up the display ?
4/Is there update regarding the speed problem ( Gdal driver issue).
5/Is there another way faster (Gvsig for instance) in displaying postgis
raster data?
Thank you to throw light for me.
Regards.
Laurent Celati.
</pre>
</blockquote>
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